GPS is too important to flight safety and other uses to jeopardize for the sake of establishing a cellular communications network that could interfere with satellite-navigation signals, said AOPA and 26 other organizations in a regulatory filing that urged denial of a license-modification application in the case.

The threat of harmful interference with GPS navigation, on which aviation depends, has not been diminished by an amendment filed by Reston, Virginia-based Ligado Networks to its license application, the groups wrote in a July 18 letter to the Federal Communications Commission. The groups were addressing Ligado’s bid to establish a network on near-GPS frequencies, reminiscent of the proposal that in 2012 forced a predecessor entity, LightSquared, into bankruptcy in the face of opposition from aviation and a range of other GPS users.

Moreover, the groups wrote, a government study “verified” that Ligado’s plan—which the company asserts would protect “certified aviation GPS devices”—still poses risk to “most other categories of GPS/GNSS receivers including those used for General Aviation and drones.”

“Ligado’s proposal appears to ignore these other GPS devices, the protection of which must be ensured by the Commission,” the letter contended.

The 27 organizations that signed the letter urged the FCC to deny Ligado Network’s pending license modification application “unless Ligado can show it has addressed the substantive GPS, aviation, SATCOM, and weather data interference concerns still outstanding in the record.”

In addition to the recent regulatory filings, in a June letter to FAA Acting Administrator Daniel K. Elwell, 11 aviation groups opposed to Ligado’s plan noted that some flight operations occur close enough to Ligado’s transmission towers to be at risk. They called on the agency to support more testing “by an impartial third-party organization” to evaluate the impact on airspace safety.

Dan Namowitz

Associate Editor Web

Associate Editor Web Dan Namowitz has been writing for AOPA in a variety of capacities since 1991. He has been a flight instructor since 1990 and is a 30-year AOPA member.